- mass exchange
- mass flow
- mass flux
- mass scale
- mass spectrometer
- mass spectrometry
- mass transport
- masstype plate
- master black
- master clock
- master controller
- master gain
- master oscillator
- master switch
- match
- matched impedance
- matching
- matching attenuation
- matching impedance
- matching transformer
- mechanical closure
- mechanical impedance
- mechanical modulator
- mechanical polishing
- mechanical quantities
- mechanical refrigeration
- mechanical refrigerator
- mechanical regulation
- mechanical strength
- mechanical test
- median
- medical cooling
- medical electrolysis
- megavolt
- megohmmeter
- melting curve
- melting losses
- melting surface
- melting time
- membrane vibration
- memory bubble
- mercury manometer
- meridian altitude
- meridian circle
- Merz unit
- mesa
- mesa diode
- mesa transistor
- mesh analysis
- mesh connection
- mesh impedance
- meshes law
- measuring amplifier
- measuring cabinet
- measuring generator
- measuring instrument
- measuring microphone
- measuring microscope
- measuring potentiometer
- measuring projector
- measuring receiver
- measuring technique
- meat pan
- mechanical analogy
- mechanical breaking
- mechanical chiller
- mechanical control
- mechanical cooling
- mechanical dehumidifier
- mechanical fastening
- mechanical stripping
- mechanical ventilation
- mechanicalstepping motor
- mechanocaloric effect
- medium range
- megagauss
- megohm
- melted ice
- melting
- melting chamber
- melting ice
- melting plane
- melting zone
- membrane manometer
- membrane valve
- mendelevium
- meniscus lens
- mercury
- mercury gauge
- metal wool
- metallized capacitor
- meter case
- methane series
- methanol
- methylamine
- microbiological stability
- microcell
- microfilm
- micrometre
- microparticle